Switched‐capacitor multilevel inverter with self‐voltage‐balancing for high‐frequency power distribution system

Abstract

Switched capacitor multilevel inverter (SCMLI) with reduced components is attractive for higher number of voltage levels due to less implementation complexity and low cost. In this study, a new family of hybrid SCMLI for high frequency power distribution system is presented to eliminate the intermediate power conversion. Firstly, a five-level SCMLI employing a single voltage source is proposed, which is further extended to nine-level (9L) with its operation. Further extension/enhancement of the proposed 9L-SCMLI for generating a higher number of voltage levels with reduced number of components is achieved on the basis of structural modification. The mathematical analysis for determination of capacitance, power loss analysis and comparative analysis has been provided in detail. A comprehensive comparison with other similar topologies is also provided to highlight the merits of the proposed topology. Simulation and experimental results are discussed for various dynamic load conditions with different output frequencies to validate the suitability of the proposed SCMLI for various high-frequency AC applications, such as renewable energy systems, microgrids, electric vehicles and so on.

Single DC source diode‐assisted hybrid multilevel inverter using a reduced number of active and passive components

“…This, in addition to the methods introduced in Section 3.1, improves the efficiency of the proposed DAH‐MLI. This lowering of losses is evident in comparison with the topologies [12–14, 22].…”

“…9 a , the proposed DAH‐MLI requires a lower number of capacitors than most to generate the same number of output voltage levels. The topologies [12–14, 19, 21, 22] utilise almost twice the number of capacitors compared to the proposed topology for the same number of voltage levels attained. The DAH‐MLI uses a lower number of switches compared to any other recently proposed topologies, as is visible in Table 4 and Fig.…”

“…The topology presented in [12, 14, 21] possesses excessively large TSV for a higher number of levels as shown in Fig. 9 c , whereas the topologies [12, 22] require more diodes to achieve the same voltage levels as observed from Fig. 9 d .…”

“…The topology in [11], discusses a circuit that uses a combination of battery cells to achieve multilevel output with the aim to reduce the number of passive devices, but the number of active devices required makes it uneconomical. The ability to generate multilevel output using single source is significantly advantageous: consequently, several single‐source topologies [12–25] have been recently proposed. In [12–15] single source‐based MLIs were proposed, but total standing voltage (TSV) and peak inverse voltage (PIV) increase drastically with the increase in the number of voltage levels.…”

“…In [17, 19, 21], topologies with low PIV were presented, but these require a considerably large number of switching devices. The topologies in [16, 22] discuss MLIs which use a combination of switches and diodes to generate higher voltage levels at very low TSV, but the number of switching devices is still very high. The topology in [25] has low TSV, PIV and capacitor requirements but is limited in its boosting capability.…”